Block of Proliferation 1 Promotes Proliferation, Invasion and Epithelial Mesenchymal Transformation in Gastric Cancer

PDGF-C promotes cell proliferation partially via downregulating BOP1

Platelet-derived growth factor C (PDGF-C) is a member of PDGF/VEGF family, which is well-known for important functions in the vascular system. It is widely reported that PDGF-C is able to modulate cell proliferation. However, it is still not very clear about this cell modulating mechanism at the molecular level. In a screening of factors regulated by PDGF-C protein, we fished out a factor called block of proliferation 1 (BOP1), which is a pivotal regulator of ribosome biogenesis and cell proliferation. In this study, we investigated the regulation of BOP1 by PDGF-C and its role in modulating cell proliferation. We found that BOP1 was downregulated at both mRNA and protein levels in cells treated with PDGF-C-containing conditioned medium. On the other hand, BOP1 was upregulated in PDGF-C deficient mice. Furthermore, we confirmed that overexpression of BOP1 inhibited HEK293A cell proliferation, whereas knockdown of BOP1 promoted cell proliferation. The mitogenic effect of PDGF-C could be attenuated by downregulation of BOP1. Our results demonstrate a clear PDGF-C-BOP1 signaling that modulates cell proliferation.

miRNA/epithelial-mesenchymal axis (EMT) axis as a key player in cancer progression and metastasis: A focus on gastric and bladder cancers

The metastasis a major hallmark of tumors that its significant is not only related to the basic research, but clinical investigations have revealed that majority of cancer deaths are due to the metastasis. The metastasis of tumor cells is significantly increased due to EMT mechanism and therefore, inhibition of EMT can reduce biological behaviors of tumor cells and improve the survival rate of patients. One of the gaps related to cancer metastasis is lack of specific focus on the EMT regulation in certain types of tumor cells. The gastric and bladder cancers are considered as two main reasons of death among patients in clinical level. Herein, the role of EMT in regulation of their progression is evaluated with a focus on the function of miRNAs. The inhibition/induction of EMT in these cancers and their ability in modulation of EMT-related factors including ZEB1/2 proteins, TGF-β, Snail and cadherin proteins are discussed. Moreover, lncRNAs and circRNAs in crosstalk of miRNA/EMT regulation in these tumors are discussed and final impact on cancer metastasis and response of tumor cells to the chemotherapy is evaluated. Moreover, the impact of miRNAs transferred by exosomes in regulation of EMT in these cancers are discussed.

Joint analysis identified FAP as a prognostic and diagnostic biomarker correlated immune infiltration in gastric cancer

Gastric cancer is one of the most malignant types of cancer in the digestive system because of its high incidence and mortality. There is a notable association between gastric cancer progression and the level and sort of immune cells infiltrating the tumor microenvironment. First, 41 up-regulated differentially expressed genes (DEGs) and 91 down-regulated DEGs were identified from the Gene Expression Omnibus (GEO) database. Among the 21 core genes, prognosis biomarkers FAP, ASPN and CTHRC1 were identified for further study via Kaplan-Meier Plotter, with FAP having the highest prognostic value among them. In addition, the ROC curves of FAP (AUC=0.992), ASPN (AUC=0.955) and CTHRC1 (AUC=0.983) also showed high diagnostic value. Then the expression and mutation levels of the biomarkers were verified by GEPIA and cBioPortal. Their high expression levels were closely correlated to the clinical stages and metastasis status of gastric cancer. Furthermore, their expression was strongly relevant to immune infiltration and macrophage marker levels. In drug response analysis, gastric cancer cell lines with overexpression of FAP and ASPN were more sensitive to PI3K and MET inhibitors, respectively. Importantly, the meta-analysis showed that FAP had an overall positive rate of 68 % (63-73 %, 95 % CI; n = 382) and the patients with high expression of FAP showed a poor prognosis in terms of OS (HR=1.82, 1.33-2.48, 95 % CI) in gastric cancer. In short, FAP, ASPN and CTHRC1 were identified as potential prognostic and diagnostic biomarkers related with immunity and might be effective therapeutic targets of gastric cancer, and the significance of FAP for the prognosis was further assessed by meta-analysis.

CNTN-1 Upregulation Induced by Low-Dose Cisplatin Promotes Malignant Progression of Lung Adenocarcinoma Cells via Activation of Epithelial-Mesenchymal Transition

Tumor metastasis and invasion are the main impediments to lung adenocarcinoma successful treatment. Previous studies demonstrate that chemotherapeutic agents can elevate the malignancy of cancer cells other than their therapeutic effects. In this study, the effects of transient low-dose cisplatin treatment on the malignant development of lung adenocarcinoma cells (A549) were detected, and the underlying epigenetic mechanisms were investigated. The findings showed that A549 cells exhibited epithelial-mesenchymal transition (EMT)-like phenotype along with malignant progression under the transient low-dose cisplatin treatment. Meanwhile, low-dose cisplatin was found to induce contactin-1 (CNTN-1) upregulation in A549 cells. Subsequently, we found that further overexpressing CNTN-1 in A549 cells obviously activated the EMT process in vitro and in vivo, and caused malignant development of A549 cells in vitro. Taken together, we conclude that low-dose cisplatin can activate the EMT process and resulting malignant progression through upregulating CNTN-1 in A549 cells. The findings provided new evidence that a low concentration of chemotherapeutic agents could facilitate the malignancy of carcinoma cells via activating the EMT process other than their therapeutic effects.